Sorry WHP, I am going to use your own example to build my case ;)
Imagine you spend HOURS working everything up in OF. Except you are working in Project Mode. You have multiple related projects. You like to look at them all at once to get the bigger picture by project. You spend hours and hours getting things JUST RIGHT. Many of your projects span a year or two, so looking at dates by project is silly/not helpful/pointless. Some of your actions within the projects have dates, some don't. The actions all have different contexts.
Phew... 3 hours later and you have the perfect doc, perfectly sorted. So now, all you want to do is get an overview, looking at the projects at once, the upcoming due dates, to get the bigger picture. Being able to see this bigger picture is part of any project management. But guess what, you CAN'T currently do this in planning mode, without PERMANENTLY resorting everything you just spent hours working on. I am using due dates as my example, but obviously this applies to any of the "view" options.
When you are in "project" head, not "context" head, having to switch to context view, then group by project and sort by date is just plain bad UI. Imagine it were in reverse – when you are in Context mode, should you have to go to Planning mode to view and sort? No, of course not, you need to see everything by its context. It doesn't relate to the train of thought you were just in. When you are in Context mode, should you be required to permanently resort the data you entered just to view it a certain way? Of course not.
I can guarantee if OF required a user to switch to Planning Mode to be able to view by date, the boards would be flaming. What we are pointing out here is an oversight in UI, or bad UI, not any change in GTD.
Right now, the sort view bar has a gray header "sort projects by" followed by sorting options. Add another gray header text header in the drop down after this with "sort actions by" with the same options. Solved.